Nasal Floor Slanting and Its Association With Nasofacial Structures

Abstract

Background and Objectives Nasal floor slanting (NFS) is an incidental radiographic finding of asymmetry in the nasal floor level. Despite its frequent appearance, however, NFS has never been properly defined, neither has its correlation with the asymmetry of the adjacent nasofacial structures been investigated. We evaluated the incidence of NFS in patients with sinonasal symptoms and its correlation with the nasofacial skeletal structures. Subjects and Method We investigated patients who underwent preoperative ostiomeatal unit (OMU) CT and facial photography. We measured the incidence of NFS and its angle in the 265 patient images, and analyzed the relationships between NFS and radiologically detected asymmetries of the adjacent nasofacial skeleton and facial asymmetry visible on a photograph. Results NFS was found in 51% of the study subjects (136/265), who were defined as the slanted group. The mean NFS angle in the slanted group was 7.7° with a standard deviation (SD) of 4.4°, ranging from 2.4° to 22.4°. The slanted group showed a higher incidence of nasal septal deviation, asymmetry in the orbit and maxillary sinus, and a larger maxillary cavity (p<0.001) than the non-slanted group. Asymmetry of the face showed a higher incidence in the slanted group (p<0.01), whereas an external nasal deviation did not show an association with NFS. Conclusion NFS is evident in about 50% of patients complaining of nasal symptoms and is associated with nasofacial skeletal asymmetry as well as asymmetry in the face.